The NYT reports that in 1990, New York City had 147,000 reported auto thefts, one for every 50 residents but last year, there were just 7,400, or one per 1,100 for a 96 percent drop in the rate of car theft. There's been a big shift in the economics of auto theft: Stealing cars is harder than it used to be, less lucrative and more likely to land you in jail. As such, people have found other things to do. The most important factor is a technological advance: engine immobilizer systems, adopted by manufacturers in the late 1990s and early 2000s. These make it essentially impossible to start a car without the ignition key, which contains a microchip uniquely programmed by the dealer to match the car.